The present invention relates to a press, an individual press, a multistage press, multistand press, transfer press, press line or similar forming machine, comprising one press slide or, if necessary, several press slides which, for the forming of sheet metal parts, can be moved up and down while interacting with the tools, and comprising a transfer device with holding devices which hold and transfer the sheet metal parts, comprising driving devices for the lifting and lowering of the holding devices and driving devices for the moving of the holding devices in the passage direction.
The transport of the sheet metal parts through presses of the above type takes place by a transfer device with a two- or three-dimensional movement of the holding devices for the sheet metal parts, with the inserting and the removal of the sheet metal parts being performed by feeders.
In U.S. Pat. No. 4,540,087, a transfer device in a transfer press is described which has two transfer bars which can be moved in three axes (three-dimensionally) and which extend horizontally and at a parallel distance from one another. In addition, the transfer device has an advancing mechanism arranged on one end of the transfer bar for generating a reciprocating movement, as well as two clamping mechanisms for the clamping and releasing movement and two stroke mechanisms for the lifting and lowering of the transfer bars.
The advancing, clamping and stroke mechanisms are each driven by a separate d.c. servomotor which are assigned to one transfer bar side; and the longitudinal, transverse and vertical strokes of the transfer bars can be varied continuously and independently of one another. The driving movements are transmitted to the drive side of the second transfer bar by a torsion bar.
U.S. Pat. No. 4,625,540 describes a transfer device in a transfer press of the two-dimensional type, in which running rails in the longitudinal dimension of the press can be lifted and lowered while being situated in front of and behind the tools. In the running rails, a frame is disposed which can be moved horizontally in the dimension of the press. Bars which extend in their length transversely with respect to the longitudinal dimension of the press and have holding devices for the sheet metal parts are arranged on the frame. In addition to the movement of the frame, the bars can be moved in a movement along the longitudinal dimension of the press. The drive of the lifting and lowering movement of the running rails and thus of the frame and the drive of the frame in the horizontal plane and of the additional movement of the bars takes place in a cam-controlled manner and thus in a restricted manner as a function of the press.
In contrast, it is an object of the invention to provide, at least with respect to the structural members of the transfer device that are to be moved, a low-mass construction which permits differing timing amounts in the subsequent machining stages or time-staggered downward and upward movements of the slides of the individual machining stages.
This and other objects are achieved by the present invention which provides a press, comprising a press frame, at least one vertically movable press slide that forms sheet metal parts while interacting with tools, and at least one transfer device with holding devices which hold and transfer the sheet metal parts through movement of the holding devices vertically and horizontally along a passage direction. Each transfer device includes at least one transport device extending in the passage direction, and vertically movable horizontal guide strips in the press frame which extend at least along a partial length of a transfer movement of the sheet metal parts and extend in front of and behind the tool or the press slide. The holding devices are displaceable in the guide strips, and each of the guide strips have structural members which receive, bear and guide the transport device. The transfer devices also include vertical guides coupled to the press frame and the guide strips, a first adjusting device coupled to the guide strips and which lifts and lowers the guide strips in the vertical guides, and a second adjusting device, separate from the first adjusting device, coupled to the transport device and which moves the transport device to thereby move the holding devices along the passage direction.
With the present invention, the utilization of a press or similar forming facility becomes more flexible. The removal of the sheet metal parts from an insertion station or from an intermediate depositing device as well as from a tool and the depositing into an intermediate depositing device or into a tool may take place separately for each individual machining stage.
The transfer device can be expanded with respect to the holding devices, for example, for double parts. One driving element for each axle as well as a separate drive for each drive side are contemplated. On each side of the press, the transport device may be a toothed belt deflected in a guide strip on which the holding device or devices are fastened. The transfer devices are constructed in the manner of modules for a successive staggered arrangement through a multistage press, press line or multistand press. In certain embodiments, the transfer device is used as an inserting and removal device (feeder). In addition to smaller overall sizes, a higher stiffness is achieved in comparison to previous feeders.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.